Electrical switch



(No Model.)

B. A. SPERRY.

ELECTRICAL SWITCH.

No. 396,439. Patented 12111.22, 1889.

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UNITED STATES PATENT Err ELMER A. SPERRY, OF CI'IIL AGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO HERBERT E. GOODMAN, OF BOSTON, BLXSSACHITSE TS.

ELECTRICAL SWITCH.

SPECIFICATION forming part of Letters Patent No. 396,439, dated January 22, 1889.

Application filed November 23, 1886. Serial No. 219,654. (No inodehl T aZZ whom it may concern.- the armature by the equal magnetic effect of Be it known that I, ELMER A. SPERRY, a separate electro-magnets being in the main citizen of the United States, residing at Chicircuit in the path of each switch-arm.

cago, in the county of Cook and State of Illi- Similar letters of reference indicate like 55 nois, have invented a certain new and useful parts in the various figures.

Improvement in Electrical Switches, of which A represents a generator of electricity; 1% l the following is a full, clear, concise, and @31- the wires of the main line, C C, the switchact description, reference being had to the acarms, and D D and I) D the contact buttons companying drawings, forming a part of this or pieces forming the terminals of the various 6o 10 specification. loop-circuits.

My invention relates to automatic switches, In Figs. 3 and I)' D indicate the termiand has for its object to provide an electric nals of a second circuit. in which the lamps switch which shall automatically switch out are indicated by crosses.

a portion of the electric circuit from which a E shows an electric magnet wound by two 6 5 I 5 portion of the current has been diverted. sets of conductors and so adjusted as to each It is well known that the currcnt-intensitv other that when the same current traverses upon the main linenear or at the point where each in opposite directions there no magthe loop or branch circuit leaves the main 'netic effect from the same upon the common line is only equal in the and limb or core. These two coils on the main line form 2o limbs each side of the loop or branches when the path for the current as it goes into and there is nothirdpassage or escape of the curcomes from the loop or branch, or a porrent from some point within said loop to that tion of same, as is shown in Fig. l. F indipart of the main line outside of a switch or catcs the armature of said magnet. The outside of the points of juncture of loop and switch-arms are connected by an insulated 2 5 main line. In other words, the exact current strip, G, pivoted to each for the purpose of as to quantity per second passes out of the simultaneousmovement. An upward pro iec loop upon the main line at the one extrmnit; lion, G, of this strip engages the armature that passes from said main line in upon the and serves to retain the contact-arms upon loop at the other, providing there is no other one set of contact:pieces or loop-terminals.

o escape, in which case, however, there is a dif- The spring H serves to move the switch when ference, and it is this dilterence or the dit't'er the armature rcle: s the same. A handle is ential action of the currents upon the main provided at I to facilitate the movement: of line or near the terminus of the loop that the switch-arm.

I propose to utilize to autmnaticallv change The letters D l) indicate the terminals of 3 5 the main-line connectors from one loop to the tlnal loop.

the next or another loop. Some of the means .I, K, and K indicate loop-circuits, in which I employ to accomplish this result are illusvarious translatin devices ma be arranged.

trated in. the accompanying drawings. The construct ion of the oppositelv-projecting Figure 1 is a diagrammatic view of an orlateral retaining-contacts in Fig. 4c is such 0 4o dinary double-line switch as used in my sys that as the armature l! is raised it breaks contem upon the main line of an electric-light tact with G butengagcs with G When th circuit for the purpose of changing the elecarmature again drops or returns to its former trical connections from one loop to another. position, it engages the stop G, which holds Fig. 2 shows its adaptation for an incandes the lower extremities of the levers upon the 5 45 cent circuit. Fig. 3 shows a switch in which right side of the eltmgated central contacts, the differential action serves to change the and upon the circuit Ii until the armature F contacts of the switch onto a new loop in is again drawn upward, when a still further which translating devices are located. Fig. movement of the arm takes place and the 4 shows a varied form of Fig. 3, in which a loop J is brought into circuit. osecond change is made. Fig. 5 shows avaried The varied form shown in Fig. 5 may be form of Fig. 1, in which the balance is upon described as follows: A centrally-pivoted armature, F, is provided with a centralizingspring, L, and a laterally-projecting stop, F, at the extremity of a projection, as shown. This stop engages an opposite laterally-projecting stop, G upon the strip G, which may be released by a movement of the stop in either direction, upward or downward, from the central position.

The letter M, Figs. 1 and 3, illustrates the outside view of a loop-switch working upon the same main circuit, which may be like or unlike the first. \Vhen the loop or branch is in the normal working condition, the path of the current is upon the main line throughout one coil of the helix to the switch-arm, to the loop, thence around the loop-circuit to the other terminal, and thence to the other switcharm through the other coil of the magnet upon the main line. In practice I prefer to wind the magnet in each switch with two strands simultaneously, the first ends of which are attached to the outer main lines and the last ends to the switch-arms, or vice versa. In this way the currents are opposite and the magnetic effects are equal.

Having thus fully described the arrangements of parts in these diagrams, I will proceed to explain their action.

Referring now to Fig. 1, it will be considered that the current flows from the generator A, through the circuit B in direction of the arrows, the lower terminal being maintained at a higher potential than the upper I11 its progress it traverses one of the coils upon the magnet E, thence through the switch-arm to the loop and around the same, energizing the various translating devices therein, thence to the other switcharm, through the remaining and opposing coil upon the magnet E, thence out upon the main circuit. The spring 11 is given a tension by the movement of the arms to the right, in which position the system is retained by the catch upon the under side of the armature, which armature is placed before the core of the magnet E, and which is attracted by the same whenever there is any appreciable difference between the incoming and outgoing currents. Suppose the loop K to be in an iron building, for instance, and a contact or ground exist between the wire and the iron of the building at any point upon said loop, as X or Y. As yet there is no interference with the normal operation of the system 3 but should another contact or ground occur upon the outside circuit or any of its loops, or even in the generator A, the current will then divide, part passing between the two points of ground, as from X to X or Y to Y, leaving only a part of the normal current to flow through one of the coils upon the magnet E. The current intensity in the other will remain'or even rise above the normal, owing to the decreased resistance exterior to the generator. fect thus obtained serves to energize the core, attract the armature F, releasing the stop G,

The differential magnetizing efand thus allow the spring H to draw the contact-point over onto the other set of terminals, D D, thus removing from circuit altogether the faulty or grounded loop and allowing for repairs, while no stoppage occurs on the main line, the current upon which is now led into the other loop, J. If the one or more co-operating grounds or crosses exist in other loops provided with a switch, such as has been described, they will also be removed from circuit by changing the connection into a new loop, leaving the line perfectly clear. However, if the other cross exists in the main line, its presence being thus indicated, the same may be removed after the plant has stopped, it being readily understood, however, that its operation upon a multiple circuit, such as is shown in Fig. 2, is substantially the same as upon the series circuit just described. The generator should be automatically controlled in each case for best general results.

It will be readily seen from the foregoing that this differential action of the ingoin g and outgoing currents to change the lin e-connectors to a new loop-circuit may be utilized in various ways, some of which are as follows:

One simple form of switch embodying the principle as shown in Fig. 3,1'n which the loop J, Fig. 1, is extended and working devices are shown therein. This auxiliary circuit K is thrown into circuit whenever a ground occurs simultaneously upon the loop K and outside circuit.

Fig. at shows the same feature, with the exception that the arms make a still further advance upon the operation from the ground in the loop K, as will readily be understood. As the laterally-prejecting catch of finger F of the armature F rises, it loses contact wit-h stop G. This allows the system to be drawn to the right by spring H, until intercepted by laterally-projecting finger G in which posi' tion the terminals of the switch-arms are in contact with the elongated terminals D D \Vhen the armature again falls, the contact last named is broken and the further movement is intercepted when the catchGr is reached by that of F The electrical c011- nections have, however, as yet not been changed, but simply slide along upon the elongated terminals D D. Upon the second operating ground in loop K this last catch is broken and the main-line circuit is again changed to the final loop J.

The alternate form shown in Fig. 5 illustrates an alternate form of differential magnetic devices. Two magnets are so adjusted as to act equally and opposedly upon a common armature centrally pivoted and so organized that when a movement takes place in either direction from this central position the switch mechanism will be released. This is accomplished by a laterally-proj ecting finger, G and an opposite laterally-projectingcatch, E connected with the armature.

It will also be readily understood that contact devices may be provided other than the arms herein mentiouedas, for instance, springs or mercury contacts without departing from the spirit of my invention; also, weights could be used in lieu of springs; but in all cases I prefer that the magnet E should be in the main circuit and not in the loop or branch circuit.

It is important that the operating-magnet should be constantly in the main circuit in order that its action may continue long enough to break any current which might arise from the switching out of the loop.

iVhat I claim is 1. In combination with a double switch adapted to be operated by a spring or equivalent, a catch organized to oppose said spring, and an electro-magnetic core wound with two coils of equal magnetizing effect, which are placed one in the circuit with each switcharm, said magnet placed so as to control and operate the catch, substantially as and for the purpose specified.

2. An electrical switch provided with two simultaneously-moving arms, a retracting device previously energized, an armature operating a catch to retain said arms in opposition to said retracting device, and differential electro-magnet in circuit with each of the two arms of said switch adapted to control the said catch, as and for purpose specified.

In combination with the main circuit, a duplex switch forming a connection between said main circuit and a loop or branch circuit, a differential magnetic system, the opposing helices of which are in electrical connection one with each arm of the switch, and an actuating mechanism, said magnet placed so as to control and operate the actuatingmechanism and the latter to operate the switch, substantially as and for the purpose specified.

4:. In a duplex switch, the combination, with simultaneously-moving switch-arms, of a retracting device, a catch to hold the same, an d. a magnet operating said catch having two helices, one in circuit with each switch-arm, substantially as and for the purpose specified.

Two loop or branch circuits terminating each in two electrical contacts, in combination with a duplex switch the arms of which are adapted to operate in connection with said contacts, and which are in connection with the main circuit through two electro-magnetic helices which oppose each other, and connect ing mechanism consisting of the catch and spring or its etpiivalent for operating said switch, said magnet placed so as to control and operate the catch, substantially as and for the purpose specified.

5. The duplex switch, substani iallysuch as described, in combination with two dilierentially acting electric helices, the circuits through which being those passing the arms of the switch, said magnets being located between said switch-arms and the points of production of the electrical currents upon the circuit, substantially as specified and shown.

7. The cmnbination ot a main line with a service-loop thereon, a duplex switch whose arms complete the ctninections with the main line, a differential magnet through which the loop-current passes in opposite directions, a retracting-spring connected with such switch, and a catch to hold such switch, said cai ch controlled by the magnet, so as when released to release the switch and permit the loop to be cut out of the main line.

In witness whereof I have hereunto sub scribed my name this 30th day of November, A. I). 1886.

ELME A. SPERRY.

VltllOSge Gno. Lxwnuxcn, .J r., J. G. Mansn. 

